let json = JSON.stringify(
    Array.from(document.querySelectorAll(".boxgrid a")).
        map(function(e){return e.href})
);


port = 5000;

fetch(`http://127.0.0.1:${port}/`, {method: "post", 
                                    body: json,
                                    headers: {
                                        'Content-Type':'application/json' 
                                    }
                                });